employee.c

/*-
 * Copyright (c) 2012 valsorym <[email protected]>.
 * All rights reserved.
 *
 * Discussion on the forums.freebsd.org.
 *  url: http://forums.freebsd.org/showthread.php?p=177208
 */

/*
 * Very simple class, for example OOD in ANSI C.
 */

#include <stdio.h>
#include <string.h>
#include <memory.h>

#include "employee.h"

/* INTERFACES */
/* Private:
 * For the experiment, the method of Private.
 */
static int goodage(int );

/* Public: */
/* Constructor & Destructor */
static struct w_employee *create(int , char *, char *);
static void destroy(struct w_employee *);

static char *setpost(struct w_employee *, char *);
static char *getpost(struct w_employee *);

/* Initialization (constructor / destructor). */
const struct w_employee_initializer w_employee = {
    .create = create, .destroy = destroy
};

/* IMPLEMENTATIONS */
/* Private: */
/*
 * In this class, the method gooage() determines whether the normal
 * age of a person.
 */
static int
goodage(int age)
{
    /*
     * Under the legislation an employee must be between the ages of
     * 18 to 60 years.
     */
    if (age >= 18 && age <= 60)
        return 1;

    return 0;
}

/* Public: */
/*
 * The constructor, allocates memory to accommodate the class,
 * initialize its elements.
 */
static struct w_employee
*create(int age, char *name, char *post)
{
    struct w_employee *self =
        (struct w_employee *)malloc(sizeof(struct w_employee));

    /* Initialize the elements. */
    /* Methods. */
    self->setpost = setpost; self->getpost = getpost;

    /* Private data. */
    if (goodage(age) == 0)
        age = 18;

    self->human = w_human.create(age, name);
    self->setpost(self, post);

    return self;
}

/*
 * The destructor frees the allocated memory in self class.
 */
static void
destroy(struct w_employee *self)
{
    if (self) {
        if (self->human)
            w_human.destroy(self->human);

        if (self->post)
            free(self->post);

        free(self);
    }
}

/*
 * Set the post of employee.
 */
static char
*setpost(struct w_employee *self, char *post)
{
    int post_len = strlen(post) + 1;

    if (self) {
        if (self->post)
            free(self->post);

        self->post = (char *)malloc(post_len * sizeof(char));
        strncpy(self->post, post, post_len);

        return self->post;
    }

    return NULL;
}

/*
 * Get the post of employee.
 */
static char
*getpost(struct w_employee *self)
{
    if (self)
        return self->post;

    return NULL;
}

/* The End. */